As it stands, Republicans have flipped 15 Democratic-held seats. Their net gain is 12 seats, since Democrats moved three GOP-held seats into their column. Democratic challengers defeated Reps. Steve Southerland (R-Fla.) and Lee Terry (R-Neb.), and the party also won the open seat in California's 31st District.

Two additional races in Louisiana's fifth and sixth districts won't be decided until a Dec. 6 runoff. Unlike the other districts listed here, votes are not currently being counted in either of those races.

Here are the nine outstanding House races:

1. Arizona's 2nd District: Rep. Ron Barber (D) v. Republican Martha McSally. Barber is currently trailing McSally by just 363 votes. The incumbent Democrat narrowly beat McSally in 2012 after 11 days of vote-counting, and this year's race could take a similarly long time to decide.

2. California's 7th District: Rep. Ami Bera (D) v. former Rep. Doug Ose (R). As of Friday afternoon, Ose was leading Bera by 2,183 votes. The Ose campaign said in a statement Thursday night that the Sacramento County Registrar still had more than 70,000 countywide ballots to be counted, some of which would be part of the district's total. A final result could come as soon as Saturday. Bera wasn't declared the winner in 2012 until after more than a week of tallying votes.

5. California's 17th District: Rep. Mike Honda (D) v. Democrat Ro Khanna. This seat will remain in Democratic hands no matter who wins. Honda currently leads by more than 4,000 votes over his Democratic challenger, who served as a deputy assistant secretary in the Commerce Department.

6. California's 9th District: Rep. Jerry McNerney (D) v. Republican Tony Amador. McNerney currently leads by 2,360 votes over his GOP challenger, a former police officer and U.S. marshal. But both parties had expected McNerney to win reelection easily, and certainly not be held to such a close margin.

8. New York's 25th District: Rep. Louise Slaughter (D) v. Republican Mark Assini. Slaughter, a senior Democrat who holds the top slot for her party on the powerful House Rules Committee, is barely holding on to her seat. Her lead on Friday was fewer than 600 votes. Her Rochester-area district was never considered to be competitive this cycle.

9. Washington's 4th District: Republicans Dan Newhouse v. Clint Didier. Republicans will keep this seat in their column regardless of whether Newhouse or Didier wins. Newhouse is currently in the lead by more than 3,000 votes.